Bereaved families and survivors of the 7/7 attacks have withdrawn a legal attempt to force the Government to hold an independent inquiry into the atrocity.

Their lawyer announced they were dropping their application for judicial review of the Home Secretary's decision not to hold an independent inquiry into the July 7 2005 London bombings.

Clifford Tibber, of Anthony Gold Solicitors, said the 25 claimants agreed that the five-month inquest into the attacks had "thoroughly investigated" many important aspects of the role of the emergency services and MI5.

They also recognise that a further inquiry would cause "further unnecessary distress" to the bereaved families, survivors and the rescuers who attended the scenes of the four bombings on the capital's transport network, he added.

But some of those behind the legal action said they still had unanswered questions, in particular about whether MI5 could have prevented the attacks if it had followed up the clues it held about the terrorists.

The judicial review application was launched in August 2007 after then-home secretary John Reid refused a request for an independent public inquiry into the attacks.

Mr Tibber said: "During the course of the inquests there were a number of matters into which the coroner was unable to inquire which still require further consideration. The inquests did however thoroughly investigate many important aspects of the role of the security service and the emergency services. The failings identified by the coroner are being addressed by all the relevant agencies.

"Against that background our clients recognise that any inquiry into those matters into which the coroner has inquired would cause further unnecessary distress to the bereaved families, those that survived and the individual members of the emergency services who attended the scenes."

Graham Foulkes, whose 22-year-old son David was killed at Edgware Road tube station, added: "The inquest did highlight failings in the operational procedures of the security services which the coroner felt unable to address. Many of these failings are still in place today. They need to be examined and scrutinised to ensure successful future national security work, and the Home Secretary needs to assure us that she is indeed looking carefully at this issue and will report on this."

The suicide bombings on three Tube trains and a double-decker bus carried out by Islamist extremists Mohammed Sidique Khan, 30, Shehzad Tanweer, 22, Hasib Hussain, 18, and Jermaine Lindsay, 19, were the worst single terrorist atrocity on British soil.